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本文第一部分讨论了沥青纤维和PAN纤维的物理特性,并断定两种纤维有基本上相同的BET表面积,0.5m~2/g,并有类似的小于0.03cc/g的总孔体积。本文概括了测定纤维的活性表面积(ASA)的实验结果。ASA是一个任意的参数,它包括在纤维晶体基础平面的边缘活性点面积的总和,也包括了空位和缺陷。已经发现ASA是在升高温度的情况下不同碳质材料的一个极好的活性指标(1)。习惯上,ASA的测定首先是将所研究的碳质材料样品在分子氧的初始压力为0.067KPa的气氛下,300℃时保持24小时。然后把样品加热至950℃,收集放出的CO和CO_2,并进行定量。计算由样品化学吸附的氧的量和脱附的CO和CO_2的量。假设一个碳晶格点吸附一个氧原子,且一个活化了的碳品格点所占的平均面积是0.083nm~2,那么就可算出ASA的值(1)。
The first part of this paper discusses the physical properties of bitumen fibers and PAN fibers and concludes that the two fibers have essentially the same BET surface area of 0.5 m 2 / g and a similar total pore volume of less than 0.03 cc / g. This article summarizes the experimental results for determining the active surface area (ASA) of fibers. The ASA is an arbitrary parameter that includes the sum of active area at the edge of the basal plane of the fiber crystal as well as gaps and defects. ASA has been found to be an excellent indicator of activity of different carbonaceous materials at elevated temperatures (1). Traditionally, the ASA was measured by first holding a sample of the carbonaceous material under study for 24 hours at 300 ° C under an atmosphere of 0.067 kPa initial molecular oxygen. The sample is then heated to 950 ° C and the released CO and CO 2 are collected and quantified. Calculate the amount of oxygen chemisorbed by the sample and the amount of CO and CO 2 desorbed. Assuming that a carbon lattice points to an oxygen atom and the average area occupied by an activated carbon lattice point is 0.083 nm ~ 2, the ASA value (1) can be calculated.